OFFSET
1,2
COMMENTS
The next terms are > 4.1*10^5. - Elmo R. Oliveira, Nov 29 2023
FORMULA
a(n) = A057195(n)/2.
EXAMPLE
For k = 14, 4^14 + 7 = 268435463 is prime.
MATHEMATICA
Select[Range[0, 5000], PrimeQ[4^# + 7] &]
PROG
(PARI) is(n)=ispseudoprime(4^n+7) \\ Charles R Greathouse IV, Jun 06 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Vincenzo Librandi, Oct 01 2012
EXTENSIONS
Extended using A057195 terms by Michel Marcus, Aug 28 2015
a(51)-a(54) derived from A057195 by Elmo R. Oliveira, Nov 29 2023
STATUS
approved